Correct, you'd have the .01uf cap across the lighting outputs, this causes the triac to trigger. Next you have the bridge between frame ground and the lighting output, the DC outputs of the bridge rectifier feed the 470 ohm resistor and the LED in series. It's a lot of parts to get LED lighting, but with the oddity of the random polarity, it's the way you have to do it.
The reason you didn't need the .01uf cap on the ERR stuff is it's included in the design of those boards.
